At issue is whether income from apartment complexes was falsified to support larger loans--which often became part of mortgage securities.

Owners of an apartment complex near Pittsburgh, who wanted to take out a mortgage on the buildings, allegedly made vacant units look occupied by turning on radios, placing shoes and mats outside doors and in one instance having a woman tell inspectors her boyfriend was asleep inside.

The owners obtained a $45.8 million loan, which was wrapped into mortgage securities and sold to investors.